It's possible the "Me" card somehow got un-set. I dunno if it's still in the same place on 10.8 as it was on 10.6, but in the Address Book application, select the card with your own data, then go to Card -> Make This My Card to re-set it. (If it's already set, that menu item will be greyed out.)

cl, it's in the same place and it is marked as my card. Must be something buggy in Camino. I notified them yesterday and they responded wanting to know the url of the page that didn't work. Maybe they'll make an update soon. Mountain Lion has a lot of bugginess to it. If you don't need to update, don't.